Counterlivering agent in red lead paint



Patented Oct. 24, 1950 My invention relates to preparations containingred lead and although applicable also to preparations whereinthered-lead-carrying vehicles are alkyd resins, phenolic resins,polyamine' resins or natural resins, alone or in any combination, theinvention is especially applicable to red-lead-in-oil paints and pastesand inks, the oil vehicle being often linseed oil. It is applicable alsoto preparations wherein the red lead is only one of a plurality ofpigments.

This application is re-filed for my inadvertently abandoned application,Serial No. 607,480, filed July 27, 1945, and is identical therewith,with respect to the descriptive parts of the two applications.

The invention concerns itself with the problem of livering, which isdefined as the progressive increase in the viscosity of a red-lead paintor the like on ageing, to a degree appreciably in excess of the originalviscosity, namely, that atthe time of manufacture. The period free oflivering may be as long as one year or as brief as a few days, dependinon the marketin and use conditions. This thickening. reaches a pointwhere the material has solidified so muchas to be no longer usable. I

- The livering is undesirable, not only because of the labornecessaryfor thinning the more or less solidified substance, but alsobecause, under certain conditions, an excessive thinning is requiredand, as a result whereof, a thinner paint film with less hiding powerand with less resistance against corrosion and abrasion results, and onetherefore of shorter life.

The expedient of packing red lead pigment separately from the vehicle fomixing by the user immediately before application, constitutes more ofan escape from rather than than a solution of the problem. The reason isthat it is timeconsuming for the user and, additionally, results are notconsistent in that this expedient imposes too great a responsibilit onthe average user, with reference to his care and skill in selecting thecorrect proportions, not to mention the possibility of using a poor orunsuitable kind of oil, and not to mention frequently preparing toomuch.

It is known to the industry, in the case of red 7 r, UNljTED STATESPATENT OFFICE COUN TERLIVERIN G AGENT IN RED LEAD PAINT Richard B.Pollak, Maywood, Calif.

No Drawing. 'Refiled for abandoned application Serial No. 607,480, July27, 1945. This application February 13, 1948, Serial No. 8,283

4 Claims. (01. 106-2 58) ment 1 of September 1, 1943, livering isfrequently encountered if the acid number of the linseed replacement oil(Federal Specification 'IT-O-37l) is 4.0 or above. In fact, if theroller mill gets hot or if the paste is not immediately reduced,livering can occur with replacement oil of acidnumber 3.0. Paintmanufacturers who formerly produced rel'lead of purity, the impuritybeing mainly litharge, have in the course of years been forced togradually increase the red lead content for the paint trade to and 97%.As a result of this improvement, the livering tendency has beenappreciably lowered, but the fact remains that, even with the 97% grade,manufacturers find themselves inconveniently restricted in their choiceof suitable vehicles. Also, even when a generally suitable vehicle isemployedQit will not infrequently react junfavorably in the presence ofonly slightly abder a near vacuum or under an inert gas like nitrogenor, carbon dioxide, or under normal atmospheric pressure but with lowtemperature over a longer period. However, every one of the foregoingmethods adds considerably to the cost and reduces the output frorn anygiven equipt,- I

Briefly described,'my invention consists of adding, to a productionbatch of red-lead-in-oil or red lead in any other vehicle, acounter-livering agent of the class of glycol ethers The glycol etherscan be used, as I discovered previously to conceiving the instantinvention, to restore already livered paints by adding to them 0.25% orover of any one or more, in combination, of the lycol ethers, saidproportions being on the basis of weight as are all other referencesthereto herein. Satisfactory results were obtained also, by the additionof 1% or more of an alcohol, such as ethyl, isopropyl, secondary butyl,or normal butyl alcohol. Accompanying the thinning action by thealcohol, was the eventual bad settling out on the part of the pigment,which result did not occur with the glycol others.

In the course of experiments for restoring livered paints, I discoveredthat a glycol other can be added to the batch when manufacturin it, and,if in suitable proportion, the glycol ether keeps the paint or paste orink or the like sufficiently fiuid for a desired period betweenmanufacture and use. If the proportion of glycol ether is too small, theproduct will still progressively body with age, and if too high, badsettling will result.

In the case of one particular 85% red lead-inoil paste, which in theabsence of the counterlivering agent, livered solid two hours aftermanufacture, the incorporation of 0.25% of a glycol ether preventedlivering. The paste so treated, was found to be still fluid at the endof one week. The amount of glycol ether that should be added, in anygiven case, is determined by a number of factors, among them, the amountof litharge, the reactivity of the vehicle, the manufacturing processemployed in making the red lead, and the length of the pre-liveringperiod that is desired.

In no case, have I found that less than.0.25-%.

of glycol ether is effective. With most preparations, I have found apercentage of about 1% suitable. With increases over 1%, the tendency ofthe red lead pigment to settle becomes increasingly pronounced until,when glycol ether is used in a quantity greater than 4%, the settlingrate becomes excessive, even in the case of low litharge content. To sumup,I have found a range of from 0.25% to 4% of glycol ether, relativelyto the amount of red lead, more or less satisfactory, conditioned, bythe lengths of the periods between manufacture and use.

In the class of glycol ethers, any one of them or any number of them maybe used in any combination and in any proportions relatively to oneanother to constitute a total glycol ether content within the limitsstated as a counterlivering agent. Among the various glycol ethers,

which are occasionally referred to also as etheralcohols, I have usedwith equal success, singly .and in various combinations, ascounter-livering agents, appropriately respectively to differentunsuitable for such manufacture. Furthermore,

it will now be possible to manufacture readymixed red-lead paints withhigher acid oils and be appropriately employed to describe red leadpaints, pastes, inks, and the like, and whether in an oil or othervehicle.

There is claimed:

1. An organic surface coating consisting essentially of a pigmentconsisting of the oxide or hydroxide of lead, a vehicle containing adrying glyceride oil which, in the absence of a counterlivering agent,will cause livering, and at least one lower saturated aliphaticether-alcohol, the weight of total ether-alcohol being not less than0.25% and not more than 4% of said pigment.

2. A non-livering pigmented composition consisting essentially of apigment consisting of the oxide or hydroxide of lead, a vehiclecontaining a drying glyceride oil which, in the absence of acounter-livering agent, will cause livering, and. at least one lowersaturated aliphatic ether-alcohol, the weight of total ether-alcoholsbeing not less than 0.25% and not more than 4% o the weight of saidpigment.

3. A non-livering pigmented composition consisting essentially of apigment consisting of the oxide or hydroxide of lead, a vehiclecontaining a dryingglyceride oil which, in the absence ofacounter-livering agent, will cause livering, and the mono-butyl etherof ethylene glycol, the weight of total glycol-ether being not less than0.25% and not more than 4% of said pigment.

4.- An organic surface coating consisting essentially of a pigmentconsisting of the oxide or hydroxide of lead, a vehicle containing adrying glyceride oil which, in the absence of a counterlivering agent,will cause livering, and the monobutyl ether of ethylene glycol, theweight of total glycol ether being not less than 0.25% and not more than4 of said pigment.

RICHARD B. POLLAK.

No references cited.

1. AN ORGANIC SURFACE COATING CONSISTING ESSENTIALLY OF A PIGMENTCONSISTING OF THE OXIDE OR HYDORXIDE OF LEAD, A VEHICLE CONTAINING ADRYING GLYCERIDE OIL WHICH, IN THE ABSENCE OF A COUNTERLIVERING AGENT,WILL CAUSE LIVERING, AND AT LEAST ONE LOWER SATURATED ALIPHATICETHER-ALCOHOL, THE WEIGHT OF TOTAL ETHER-ALCOHOL BEING NOT LESS THAN0.25% AND NOT MORE THAN 4% OF SAID PIGMENT.